The present invention relates to a switching regulator for maintaining the voltage to be applied to a load at a constant level even when the power supply voltage or load varies, and more particularly to a switching regulator of the converter type.
Switching regulators of the converter type include one employing a blocking oscillator. As is well known, the blocking oscillator includes a transformer serving as a feedback circuit. The voltage of a d.c. power supply is fed to the blocking oscillator, in which the voltage is inverted to a.c. voltage. This a.c. voltage appears at the secondary winding of the transformer of the blocking oscillator. The winding is connected to a rectifying smoothing circuit, by which the a.c. voltage is converted to d.c. and supplied to the load.
Such a switching regulator is provided with a stabilizing circuit by which the voltage to be fed to the load is maintained at a constant level even in the presence of variations of the load. This circuit includes a transistor connected in series with the rectifying smoothing circuit and the load as positioned therebetween. Since the transistor is usually in conduction, the current flowing through the transistor produces a heat loss, resulting in a reduced efficiency.